"if the battery in a mechanical mod over-discharges and the device doesn't contain enough air holes to allow the battery to vent, there is a risk of explosion.".

elizabeth loder, md, professor of neurology, harvard medical school; chief, division of headache, brigham & women's hospital... january 2018  (23).

bruschi, who said he never fell into smoking cigarettes though he enjoys a cigar now and then, has a favorable view of raising the tobacco purchase age, too..